Orthorhombic (Ru, Mn)2O3: A superior electrocatalyst for acidic oxygen evolution reaction

The development of efficient oxygen evolution reaction (OER) electrocatalysts is of vital importance for acidic water decomposition. Currently, the rutile structured RuO 2 is considered to be the best candidate and has been studied widely. However, the state-of-the-art rutile RuO 2 still suffers from unsatisfactory activity and stability, while other crystalline structures of Ru-based oxides are seldom reported as OER electrocatalysts. The present work, for the first time, successfully synthesizes orthorhombic (Ru, Mn) 2 O 3 electrocatalyst through cation exchange. The orthorhombic (Ru, Mn) 2 O 3 particles exhibit the outstanding electrocatalysis performance as OER electrocatalyst, showing an ultralow overpotential of 168 mV at 10 mA cm −2 in acidic water and good stability in 40 h of OER. The outstanding electrocatalysis performance is attributed to the distinct Ru d -band structure together with the larger surface density of Ru active site, which reduces the free energy of the rate-limiting step during OER.